Edward L. Biersmith, ill,' J. Hinton, R. Normand, and G. Raymond Northeast Louisiana University Monroe. 71201
I
Group Organic Chemistry
Some time ago we had an opportunity to examine and t o evaluate o w undergraduate organic lahoratory program. One obvious ouestion we asked ourselves was how could we -~~~~~ improve the level of instruction in our program. Herein, we describe the results of a two-vear studv of our second-semester curriculum. The indlvldual Approach (A Man for All Seasons) Our program, like many others, was based on a principle passed onto us more by tradition than anything else. In this paper we refer to it as the individual approach. This method of instruction directs each student t o work through each laboratory experiment independently. The student researches the experiment, sets u p the equipment, perform$ the experiment;makes observations dur& the experiment, and conclusions after the experiment is completed. I t was our ohsewation that this approach was less than satisfactory for a portion of our student body. Many of the students worked toeether before. durine, -. and after each of the experiments. A eertain combination of unknown factors appeared to produce leaders and followers for each one of the experiments. Audio-visual aids and prelahoratory instruction seemed to improve the situation hut not solve i t completely. In the remaining cases the students were observed watching one or two students set up the apparatus for an experiment and following what they did step-by-step until the experiment was completed. But as the information was passed on from one student t o another and in turn from one lahoratory bench to another, precious time was lost. I t was inevitable that some students finished the experiment only in haste and with poor results. Others did not finish the experiment a t all. Our conclusion was that many ofthe students were really workinn in erouDs on each ex~eriment.I t was a t this point we proposed to design and st;dy an alternative instruitiona1 Droeram. One where m o u ~interaction was included by desigLand not left t o ;haice. I t was a group approach modeled after the modern industrial lahoratory. ~~~
~.~
Table 1. I.
~~
The Group Approach (Three Heads Are Better Than One) Our plan was t o divide each lahoratory into two sections. Section one would work as individuals and section two in groups of three. At the end of each step of a multiple step svnthesis the students would be eiven an exam. The average scores of the students working independently would be compared with the average scores of the students working in groups. If the average scores for the memhers of groups were better than the average scores of individuals we had made an improvement in tbe mode of instruction for the program. Membershio in the Grouo
Members in the groups were selected a t random from the class roster from each lahoratorv. The classes were divided as evenly as possible into groips and individuals. Each member of the group was given a title. There were a chief chemist, a lahoratory technician, and a production analyst. A portion of this work was presented at the 29th Southwest Regional Meeting of the American Chemical Society, El Paso, Texas, Decemher 1973. 1 Author to whom correspondence should he addressed.
Operational Objectives
of
the Chief
Chemirt
Before coming to the laboratory A. Research the experiment 1. Select a synthesis from the literature a. Organic Synthesis : b. Organic Reactionr C. JOUrna16 2. Reference data for chemicals used in the experiment a. Reference physical conrtantr, rolubilitier. molecular weights b. Reference spectral Information of reactants and Products Reference theoretical aspects of the experimen- , C. tal procedure 1. Mechanirm(r) of reaction($ 2. Side reactions d. Reference alternative chemical ryntharir B. Laboratory manual 1. Prepare it table of physical constants of reactants and P I O ~ U C ~ using S CRC format 2 . Prepare a table of experimental equipment a. Sire b. Description C. Quantlty 3. Prepare a table of reactants and product9 a. Quantity b. Names C. StrUCtUmI 4. Record the selected experimental procedure in detail 5 . summarize the entire experiment using flow sheet
*..-,,.,-. .".=*
11.
he day of the experiment
Present the laboratory manual to the laboratory technician and t o the production analyst Review the highlightr of the experimental procedure with memberr of the group C. Begin the experiment D. Time the memberr of the group 1. A D D B T ~ ~ set US UD 2. wiighingr 3. Reaction 4. Recovery of crude product Purity check of crude product-chemical and 5. spectral data 6. Purification of the crude product 7. Puritv check of the Durifiea Droduct--chemical and spec& data E. Stand by to assist memberr of the group in setting up additional pieces of equipment, prepare rolutionr, analyze data Receive observations from the laboratory technician and F. the production analyst After the emeriment A. B.
Ill.
All were working under the supervision of a group leader, the laboratory instructor. Operational Objectives for the Group Members
Table 1 shows the operational objectives for the chief chemist. He has the major responsibility for the experiment. He is to assume that the lahoratory technician and the production analyst are proficient in their respective areas of specialization but they will ultimately need his direction to complete the experiment. He researches various methods to synthesize the compound desired and selects the one method he judges will give the maximum yield in the minimum amount of time. He presents his plan to the technician and the analyst in the form described. During the experiment he monitors their progress by recording the amount of time it takes them to complete each of their duties. After the experiment is completed he goes over the results with the members of the group recording their ohservations and any decisions the group makes during the Volume 52, Number 9, September 1975 / 593
Table 2.
IV.
v.
VI. VII. VIIi. IX. X. XI.
XII. .XIII. XIV.
xv.
XVI.
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Operational Objectives of the Laboratory Technician
Receive experimental Procedure from chief chemist Set up apparatus rapidly Receive welshed quantities o f reactants from Droduction analyst Begin reaction Make oblervatlons durlna the reaction Stop reaction Recover crude Product Deliver crude product t o production analyst for purity check Disalremble apparatus Receive analysis from production analyst DO one of three things A. Purify omduct (GO t o xlll 8. ~ e p e i experimknt t (Go t i 11) C. End experiment (Go t o XVI) Purify crude product-recryrtalliration. distillation Return purified product t o production analyst for analysis Receive analysis from Droduction analyst DO one of t w o things A. Purify product agaln (Go t o X i I ) B. End emeriment fGo . to XVll End experi&nt
experiment. Ultimately he reviews the results of the group's synthetic efforts with the group leader. Tahle 2 describes the operational objectives for the laboratory technician. Principally he sets up the apparatus, runs the reaction, and purifies the product. He is encouraged to study the entire experiment but be impressed with the fact that his immediate responsibility in the group is for the technical aspects of the experiment. He records his observations in a laboratory notebook and reports them to the chief chemist after the experiment is completed. Tahle 3 shows the operational objectives for the production analyst. H e performs the weighings, the yield calculations, and guarantees the purity of the product. He too is encouraged to study the entire experiment but his principle responsihility in the group is for the analytical facets of the experiment. He records his observations in a laboratory notebook and reports them to the chief chemist after the experiment is completed. Selection of Experiments The individual approach is followed for the first two experiments. A number of students for varied reasons do not enter the second-semester program immediately after they complete the first-semester program and this method acclimatizes the students. Also we needed an evaluation of each student (vida infra) before the laboratories were divided into sections. Once the division is made the students work on m u l t i ~ l e step synthesis. A number are available to choose from2 w e selected two: the svnthesis of sulfanilimide and the svnthesis of p-nitroaniline. Multi-step syntheses fit the industrial model and, if there are three steps or more, permit the members of a group to assume each role in the group a t least one time during the synthesis. Two three-hour laboratory periods are scheduled for each experiment. One period is for the preparatory step and the other for the purification step. The program is flexible enough to permit the students t o repeat an experiment if their results are poor. In fact they are encouraged t o do so. In this fashion the students who are a t a formative period in their development are conditioned to expect to repeat experiments. The Exams
Exams were administered to the students according to a
rea announced schedule. Exam questions were selected t o cover each experiment or step of a syntheqis. There were usually three qualitative questions and t 6 o quantitative questions. Every student took the same exam. McFarland, J. W., "Organic Laboratory Chemistry," Moahy, C. V., St. Louis, Missouri, 1969, pp. 216217; Adams, R., Johnson, J. R., Wilcox, C. F., "Laboratory Experiments in Organic Chemistry," 5th Ed., New York, pp. 321-322. 594 / Journalof ChemicalEducation
Table 3. I. 11. 111.
IV.
v.
VI.
Operational Objectives of the Production Analyst Receive axoerimental orocedure from chief chemlrt Note quantitter of rtartlng m a w alr neeoea welsh odr suantll#err e q u m o De over we ghea start ng ma!crmlr t o laboratory technicom CB a l a t e tneoratcal y w a o f tns p r o d m Ready analytical tools
-.
.~
Nmr Recelve crude product from the laboratory technician Run purity check on crude product A. TIC B. GC Return crude product t o the technician If Impure Receive purified Product from laboratory technician Run Purity check on purified Product A. TIC B. GC Corroborate purity of product A. Mixed melting point B. IT spectra C. N m r spectra Weigh purified Product Calculate axpqrimental yield Deliver Purified Product and CalCUlationr t o chief chemist D.
VII. VIII. IX. X. XI. XII.
XIiI. XIV.
xv.
Tabla 4.
Average Achievements for Individuals i n G~DUPS
Average (%I Exams 1-2
Na
Average (%) Exams 3-7
Average Ner Gain (Losrl ( % I
aN~mbe of~students w i t h the average rcore on exams one and two, given in column one.
Table 5.
Average Achievements for Individuals
Average (%I Exams 1-2
No
Average 1%) Exams 3-7
Average Net Gain (Losrl 1%)
a N ~ m b e of r students with the average rcore on exams one and two, given i n column one.
Results
Part One
T o establish a base line for comoarison each student was given two exams before the labor&ry sections were divided. Tables 4 and 5 show the average achievements for individuals in groups and the average achievements for individuals. res~ectivelv.In each table, column one lists the average on the first two exams; column two shows the number of students with that average; column three gives the average of exams three through seven for the students listed in column two; and column four gives the difference between columns three and one. A comparison of the data in these two tables is quite interesting. Students working in groups and with averages of 70% or lower on the first two exams demonstrated greater achievement on exams three throueh seven than those workine as individuals. For example &dents who averaged 50% on'the first two exams averaeed 82%on the next five exams working as members of a group for an average net gain of 32%. Under similar, conditions students who averaged 50% on the first two exams but worked as individuals averaged 68%
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on exams three through seven for an average net gain of 18%. Students working as individuals with averages of 80% or hieher on the first two exams demonstrated a smaller loss inachievement than those working as members of a group. For examole students who averaged 90% on the first two exams working as individuals averaged 87% on the next five exams for an average net loss of 3%. Under similar conditions students with an average of 90% on the first two exams but working as members of a group averaged 78% on exams three through seven for an average net loss of lZ%.3 The small number of students involved in the program precluded any statistical significance4 for the data but we feel two distinct trends are present. Students with incomine averaees of 80% or hieher show hetter results workine inothe tgditional man&, independently. But students with incomine averaees of 70% or lower show a sienificantlv greater achievement working as members of a group.
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Part Two
Encouraged by these results we proposed a second study. We proposed that the entire second semester class work in groups of three. This would give us greater numbers to work with and it would permit us t o check the reproducibility of our earlier results. Secondly, we proposed to take the students' average scores for the first two exams and nlace them bv averaee into as manv combinations as oossib ~ (nine e in ail). We arbitrarilv selected three mouo classifications. Students with average scores on t h e fir& two exams of lower than 70% were classified in a low group signified by the letter L. Students with average scores from 70-85% were classified in a medium group signified by the letter M. Students with average scores greater than 85% were classified in a high group signified by the letter H. Our plan was to study the composition of the students in a group to see if we could determine what combination of students would afford the greatest improvement in instruction. Table 6 shows the average achievement for individuals in groups. We observed an average net gain for students who averaeed 70% or lower on the first two exams. For students with 80% average on the first two exams we observed no chanee. For students who averaee - 90% or hieher - on the first two exams we observed an average net loss. The results follow the trends established bv our first studv. Table 7 shows the average achievements for groups by classification. Because of the limited number of students in the program we were unable to generate large numbers of proups in each classification. One group is missing, HHM. The b r e ~ i m i n a rresults ~ tend to indicate the average net gains are recorded by groups containing two or more students with averages of less than 70%.
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Observations and Comments During the course of o w study many intriguing questions presented themselves. In most cases the limits of our study did not permit us to answer these questions fully. Two are worth mentioning. In the first part of this study we placed great emphasis on monitoring the time it took to perform an experiment. The idea was to emulate the industrial credo, "Time is monev." Another related idea was to comoare the vields obtaiied by groups with the yields obtainedby indivihuals. One sneaks to the efficiencv of the mouos and the other t o the q;ality of work they priduced. We found that reeardless of the comoosition of the groups they consiste&ly finished ahead of the students workine as individuals. Thev did this without sacrificing and in most instances with the qu&ty of their better yields. We could not relate these results directly to the group
approach, however. The chief chemists in the groups were permitted t o select exoeriments from the literature. Thev here instructed by thkgroup leader to look for ways to cut time and improve yields but we could not be certain that these were the only factors that influenced their final decision. I t was, for example, highly probable that a chief chemist selected one experimental approach over another because it began with the largest amount of starting material. There were simply too many variables to correlate. Another question we would like to have answered was "What makes a good chief chemist?" We can say that, based on our observations, the above average students did not alwavs emeree as leaders in a mouo. In fact even when the rdle-was haided to them they seemed frustrated and awed bv the task. I t aooeared that manv felt the erouo was holding them back in' some way, pre;enting tiemAfrom doing the job they wanted to do. Thev were auick to claim responsih;ity forthe groups success but equaily as quick in blaming the others for a failure. One oossihle exolanation is that t h i above average student did not get where he is by working with others but by winning one on one battles for grades with his classmates. The present educational system may reward the individuals and discourage them from sharing information and solving problems together.5 Student Opinions The student resoonse was extremelv favorable from the beginning of the project to the end. L&.S than 5% of those selected to work in erouos reauested to work as individuals and less than 3% dropped outof groups after the study had begun. The attitude of the students was not measured by ad=A regression toward the mean is observed for measurements taken at the extreme limits of the study. Lord, F. M., "Elementary Models of Measuring Change," in "Problems in Measuring Change," Chap. 2, University of Wisconsin Press, Madison, Wisconsin, 1963. pp. 21-38. A test (see also footnote 5) on the difference between means gave a value of 1.026 which is not significant. Edwards, A. L., "Statistical Methods," 2nd. Ed., Holt, Rinehart and Winston, New York, 1967, p. 211. Results similar to this have been summarized by Zander, A. F., "Team Spirit versus the Individual Achiever," in "Psychology Today," 8,64 (1974).
*
Table 6.
Average Achievementsfor Individuals in Grouur
Average 1%) Exam6 1-2
Na
Avemge 1%) Exams 3-7
Average Net G a i n 1 1 04 1%)
a N ~ m b e rof rtudents w i t h t h e average score on examr one and t w o , given In column one.
Table 7.
Average Achievements of Grouus bv C l a a
c1a.riiicationa
Nb
Average N e t G a i n (Loss) 1%)
LLL LLM LLH MML LHH MMM MMH MHH HHH a Range of rfuaenr averages on examr one ana t w o : L , ower t n a n 70%; hr, from 7090-85~,; h , g r e a t e r tnan 8 5 r .
h h ~ m b e rof groUDr
Wlth
tne Class flcat'ull gown
10 co
dmn one.
Volum 52, Number 9, September 1975 / 595
ministering a n exam, h u t each student was asked a t the end of the semester t o compare his reaction t o working in a group with his reaction to working as individuals. Their general response is exemplified by the comments recorded below
I liked working in gioucs very much. The results were usually better and we got done a lot quicker. Playing a new role each week was fun. You could find out what different chemists do in a lab. When I goofed up as an individual therk was no one to blame but me. Working in a group you shared the reward for success and you shared the blame for failure. Working in groups was easy and hard. Ttie people were hard to get along with at first but the work was a Lot easier because you had less to do., I have always needed extra help in my laboratory courses. Working in a group, I always had someone there to help me. Group achievements are more satisfying.
Conclusions Overall the data suggests that the group approach offers a n alternative mode of instruction for the low achievers in the class. T h e program could, we feel, work just as well for a freshman chemistry course or a chemistry course for nonmajors. We propose to examine these possibilities and hopefully expand the study to include larger institutions with more students and to a number of smaller institutions such as community colleges. Acknowledgment We wish t o thank Dr. Robert Wysocki, Director of the Academic Computer Center, for his cooperation and many helpful discussions. We also would like to thank the Division of Chemical Education of the American Chemical Society for support of this research by a grant from the DuPont Small Grants Program.
